U.S. Pat. No. 3,244,479 discloses a method for regenerating gauze catalysts in situ. The discussed catalyst, of 90% platinum and 10% rhodium, consists of three layers of 80 mesh, 3 mil gauze.
U.S. Pat. No. 2,831,752 discloses a combination catalyst body employing gauze and granular material and a method for activating new catalysts and reactivating spent catalysts. The catalyst comprises at least one metallic gauze superimposed on a granular refractory material covered with a metallic coating. In normal practices, the granular material is about 6 to 10 mesh and is formed into a bed of about 3/4 to 11/2 inch (1.9 to 3.8 cm) thick and the overlayer comprises a single gauze. When more than one layer of gauze is employed, the layers are separated by 1/4 inch (0.635 cm) layers of 6 to 10 mesh porcelain chips.
U.S. Pat. No. 2,975,144 discloses a method of catalyst support which eliminates contact of the catalyst with heat conductive holders, clamps or other metallic or heat conductive surfaces. The apparatus is thus constructed in such a manner that the catalyst temperature is as uniform as possible and that heat dissipation and loss of heat due to radiation is minimized. In a preferred embodiment, the wires that make up the gauze are of a thickness of about 0.16 to 0.20 mm. In addition, several layers of such catalyst gauzes, of unspecified mesh size, are placed one over the other to permit the use of a higher velocity of reaction gases.
U.S. Pat. No. 3,056,655 discloses a reactor design in which either catalyst gauze or finely divided catalyst particles are supported on layers of inert pellets which range in size from fine particles (1/8 inch [0.32 cm] cylinders) immediately underneath the catalyst layer to relatively coarse pellets (5/8 inch [1.59 cm] cylinders) at the downstream size of the reactor which are, in turn, supported on an insulating refractory plate. When catalyst gauze is used, the layer of graded pellets is optional. The purpose of the refractory plate is to insulate the catalyst from the metal surfaces of the heat exchanger. The inert pellets serve as catalyst support.
U.S. Pat. No. 3,545,939 discloses a support system for the catalyst used in the production of hydrogen cyanide in a conventional reactor. The support system consists of sillimanite grid tiles which support a bed of graded ceramic pellets--a layer of 5/8 inch (1.59 cm) pellets cover the tiles, on top of which is a layer of 3/8 inch (0.95 cm) pellets, which is covered by a layer of 1/4 inch (0.635 cm) pellets. One additional layer of ceramic pellets cover the 1/4 inch (0.635 cm) pellets. Covering the ceramic pellets is a corrugated ceramic material which supports several layers of platinum-rhodium gauze pads.
U.S. Pat. No. 4,469,666 discloses the design of a catalyst pack the purpose of which is to improve the durability of platinum group metal catalyst gauzes used in the production of hydrocyanic acid. Improved durability implies that the same conversion efficiency of ammonia with less precious metal or that with the same quantity of precious metal, greater conversion is obtained. The catalyst pack is described in U.S. 4,469,666 as "a pack of woven metallic gauzes wherein at least some of the gauzes disposed at or towards the front of the pack are made from wire having a cross-sectional area greater than at least some of the gauzes disposed at
or towards the rear of the pack. The ,front, of the pack is considered to be that portion of the pack which gas entering the pack contacts first. ... [For more than two stages,] the cross-sectional area of the wire of the gauze or gauzes in any one stage is greater than the cross-sectional area of the wire of the gauzes or gauzes in the next succeeding stage considered in the direction of the flow of reactants through the unit".